Light source apparatus and projector

ABSTRACT

A light source apparatus according to an aspect of the present disclosure includes a light source section that emits first light and excitation light having a first wavelength band, a light guide that causes the first light emitted from the light source section to propagate, a wavelength converter including a phosphor that emits second light having a wavelength band different from the wavelength band of the excitation light when the wavelength converter is excited with the excitation light emitted from the light source section, and a light combiner that combines the first light having exited out of the light guide with the second light having exited out of the wavelength converter. The light guide and the wavelength converter are disposed side by side, and a light transmissive member that transmits the first light is provided between the light source section and the light guide.

The present application is based on, and claims priority from JPApplication Serial Number 2018-241204, filed Dec. 25, 2018, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a light source apparatus and aprojector.

2. Related Art

As a light source apparatus used in a projector, there has been aproposed light source apparatus using fluorescence emitted from aphosphor when the phosphor is irradiated with excitation light emittedfrom a light emitting device. JP-T-2017-536664 discloses an illuminatorincluding a rod-shaped ceramic element providing a wavelength conversioneffect and a light emitting diode (LED) that emits excitation light andso configured that the excitation light is caused to enter the ceramicelement via a side surface thereof and the resultant converted light isextracted via an end surface of the ceramic element.

As described in JP-T-2017-536664, causing the light emitted from the LEDto enter the wavelength conversion member allows generation of lighthaving a wavelength different from the wavelength of the light emittedfrom the LED. For example, when the wavelength conversion membercontains a yellow phosphor, yellow light can be generated from bluelight emitted from the LED. To generate white light necessary as a lightsource apparatus fora projector, however, a light source that emits theblue light and a light combining element or any other optical systemthat combines the blue light and the yellow light with each other needto be separately provided in addition to the illuminator disclosed inJP-T-2017-536664. As a result, there is a problem of an increase in thesize of the light source apparatus. Further, generating color lightinstead of white light also requires an optical system for combining thefluorescence with the other color light and therefore has the problem ofan increase in the size of the light source apparatus.

SUMMARY

A light source apparatus according to an aspect of the presentdisclosure includes a light source section that emits first light andexcitation light having a first wavelength band, a light guide thatcauses the first light emitted from the light source section topropagate, a wavelength converter including a phosphor that emits secondlight having a wavelength band different from the wavelength band of theexcitation light when the wavelength converter is excited with theexcitation light emitted from the light source section, and a lightcombiner that combines the first light having exited out of the lightguide with the second light having exited out of the wavelengthconverter. The light guide and the wavelength converter are disposedside by side, and a light transmissive member that transmits the firstlight is provided between the light source section and the light guide.

In the light source apparatus according to the aspect of the presentdisclosure, the light guide may have a first end surface and a secondend surface that face each other and a first side surface thatintersects the first end surface and the second end surface. Thewavelength converter may have a third end surface and a fourth endsurface that face each other and a second side surface that intersectsthe third end surface and the fourth end surface. The light sourcesection may be provided in a position where the light source sectionfaces the first side surface and the second side surface. The lighttransmissive member may be provided between the light source section andthe first side surface.

In the light source apparatus according to the aspect of the presentdisclosure, the light combiner may be disposed in a position where thelight combiner faces the second end surface and the fourth end surface.

In the light source apparatus according to the aspect of the presentdisclosure, the light combiner may include a prism that faces the secondend surface and a dichroic prism that faces the fourth end surface.

In the light source apparatus according to the aspect of the presentdisclosure, the light transmissive member may be made of transparentresin.

In the light source apparatus according to the aspect of the presentdisclosure, a refractive index of the light transmissive member may beequal to a refractive index of the light guide.

In the light source apparatus according to the aspect of the presentdisclosure, the light transmissive member may be in contact with thelight source section and the light guide.

In the light source apparatus according to the aspect of the presentdisclosure, the light guide and the wavelength converter may be sodisposed that the light guide and the wavelength converter are adjacentto each other and a lengthwise direction of the light guide is parallelto a lengthwise direction of the wavelength converter.

In the light source apparatus according to the aspect of the presentdisclosure, the light source section may include a light emitting diodelight source.

In the light source apparatus according to the aspect of the presentdisclosure, the first light may be blue light, the second light may beyellow fluorescence, the light combiner may combine the first light andthe second light with each other into white combined light, and thewhite combined light may exit out of the light combiner.

A projector according to another aspect of the present disclosureincludes the light source apparatus according to the aspect of thepresent disclosure, a light modulator that modulates light from thelight source apparatus in accordance with image information, and aprojection optical apparatus that projects the light modulated by thelight modulator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a projector according toa first embodiment.

FIG. 2 is a plan view of a light source apparatus.

FIG. 3 is a side view of the light source apparatus.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2.

FIG. 5 is a side view of a light source apparatus according to a secondembodiment.

FIG. 6 is a plan view of a light source apparatus according to a thirdembodiment.

FIG. 7 is a schematic configuration diagram of a projector according toa fourth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

A first embodiment of the present disclosure will be described belowwith reference to FIGS. 1 to 4.

A projector according to the present embodiment is an example of aliquid crystal projector using a liquid crystal panel as a lightmodulator.

FIG. 1 is a schematic configuration diagram of a projector 1 accordingto the first embodiment.

In the following drawings, components are drawn at different dimensionalscales in some cases for clarity of each of the components.

The projector 1 according to the first embodiment is a projection-typeimage display apparatus that projects a color image on a screen(projection receiving surface) SCR. The projector 1 uses three lightmodulators corresponding to color light formed of red light LR, greenlight LG, and blue light LB.

The projector 1 includes a light source apparatus 2, a uniformillumination system 40, a color separation system 3, a light modulator4R, a light modulator 4G, a light modulator 4B, a light combining system5, and a projection optical apparatus 6, as shown in FIG. 1.

The light source apparatus 2 emits illumination light WL toward theuniform illumination system 40. A detailed configuration of the lightsource apparatus 2 will be described later in detail.

The uniform illumination system 40 includes an optical integrationsystem 31, a polarization converter 32, and a superimposing system 33.The optical integration system 31 includes a first lens array 31 a and asecond lens array 31 b. The uniform illumination system 40 homogenizesthe intensity distribution of the illumination light WL, which isemitted from the light source apparatus 2, at each of the lightmodulators 4R, 4G, and 4B, which are each a region to be illuminated.The illumination light WL having exited out of the uniform illuminationsystem 40 enters the color separation system 3.

The color separation system 3 separates the illumination light WL, whichis white light, into the red light LR, the green light LG, and the bluelight LB. The color separation system 3 includes a first dichroic mirror7 a, a second dichroic mirror 7 b, a first reflection mirror 8 a, asecond reflection mirror 8 b, a third reflection mirror 8 c, a firstrelay lens 9 a, and a second relay lens 9 b.

The first dichroic mirror 7 a separates the illumination light WL fromthe light source apparatus 2 into the red light LR and the other light(green light LG and blue light LB). The first dichroic mirror 7 atransmits the separated red light LR and reflects the other light (greenlight LG and blue light LB). On the other hand, the second dichroicmirror 7 b separates the other light into the green light LG and theblue light LB. The second dichroic mirror 7 b reflects the separatedgreen light LG and transmits the blue light LB.

The first reflection mirror 8 a is disposed in the optical path of thered light LR and reflects the red light LR having passed through thefirst dichroic mirror 7 a toward the light modulator 4R. On the otherhand, the second reflection mirror 8 b and the third reflection mirror 8c are disposed in the optical path of the blue light LB and reflect theblue light LB having passed through the second dichroic mirror 7 btoward the light modulator 4B. The green light LG is reflected off thesecond dichroic mirror 7 b toward the light modulator 4G.

The first relay lens 9 a and the second relay lens 9 b are disposed inthe optical path of the blue light LB on the light exiting side of thesecond dichroic mirror 7 b. The first relay lens 9 a and the secondrelay lens 9 b correct the difference in illumination distribution ofthe blue light LB from those of the red light LR and the green light LGresulting from the fact that the optical path of the blue light LB islonger than the optical paths of the red light LR and the green lightLG.

The light modulator 4R modulates the red light LR in accordance withimage information to form image light corresponding to the red light LR.The light modulator 4G modulates the green light LG in accordance withimage information to form image light corresponding to the green lightLG. The light modulator 4B modulates the blue light LB in accordancewith image information to form image light corresponding to the bluelight LB.

The light modulators 4R, 4G, and 4B are each formed, for example, of atransmissive liquid crystal panel. Polarizers (not shown) are disposedon the light incident side and the light exiting side of each of theliquid crystal panels and each transmit only light linearly polarized ina specific direction.

Field lenses 10R, 10G, and 10G are disposed on the light incident sideof the light modulators 4R, 4G, and 4B, respectively. The field lenses10R, 10G, and 10B parallelize the chief rays of the red light LR, thegreen light LG, and the blue light LB to be incident on the lightmodulators 4R, 4G, and 4B, respectively.

The light combining system 5, on which the image light emitted from eachof the light modulators 4R, 4G, and 4B is incident, combines the imagelight corresponding to the red light LR, the image light correspondingto the green light LG, and the image light corresponding to the bluelight LB with one another and causes the combined image light to exittoward the projection optical apparatus 6. The light combining system 5is formed, for example, of a cross dichroic prism.

The projection optical apparatus 6 is formed of a plurality ofprojection lenses. The projection optical apparatus 6 enlarges thecombined image light from the light combining systems 5 and projects theenlarged image light toward a screen SCR. An image is thus displayed onthe screen SCR.

The light source apparatus 2 will be described below.

FIG. 2 is a plan view showing a schematic configuration of the lightsource apparatus 2. FIG. 3 is a side view of the light source apparatus2 viewed from the side facing a light guiding rod 51. FIG. 4 is across-sectional view of the light source apparatus 2 taken along theline IV-IV in FIG. 2.

The light source apparatus 2 includes a light guiding rod 51 (lightguide), a wavelength conversion rod 58 (wavelength converter), a lightsource section 62, a light transmissive member 65, a light combiner 53,an angle converter 56, and a collimator lens 57, as shown in FIGS. 2 and3.

The light guiding rod 51 has a quadrangular columnar shape having sixsurfaces. The six surfaces include two end surfaces 51 a and 51 b, whichface each other, and four side surfaces 51 c 1, 51 c 3, 51 c 5, and 51 c7, which intersect the two end surfaces 51 a and 51 b.

In the following description, the end surface 51 a is referred to as afirst end surface 51 a, and the end surface 51 b is referred to as asecond end surface 51 b. The first end surface 51 a is an end surface ofthe light guiding rod 51 that is the end surface located on the sidefarther from the light combiner 53, which will be described later, andthe second end surface 51 b is an end surface of the light guiding rod51 that is the end surface which faces the first end surface 51 a andvia which light exits out of the light guiding rod 51. The side surface51 c 1 is referred to as a first side surface 51 c 1, the side surface51 c 3 is referred to as a third side surface 51 c 3, the side surface51 c 5 is referred to as a fifth side surface 51 c 5, and the sidesurface 51 c 7 is referred to as a seventh side surface 51 c 7. Thedirection in which the first end surface 51 a and the second end surface51 b face each other is defined as a lengthwise direction N1 of thelight guiding rod 51.

Similarly, the wavelength conversion rod 58 has a quadrangular columnarshape having six surfaces. The six surfaces include two end surfaces 58a and 58 b, which face each other, and four side surfaces 58 c 2, 58 c4, 58 c 6, and 58 c 8, which intersect the two end surfaces 58 a and 58b.

In the following description, the end surface 58 a is referred to as athird end surface 58 a, and the end surface 58 b is referred to as afourth end surface 58 b. The third end surface 58 a is an end surface ofthe wavelength conversion rod 58 that is the end surface located on theside on which the first end surface 51 a of the light guiding rod 51 islocated, the fourth end surface 58 b is an end surface of the wavelengthconversion rod 58 that is the end surface which faces the third endsurface 58 a and via which light exits out of the wavelength conversionrod 58. The side surface 58 c 2 is referred to as a second side surface58 c 2, the side surface 58 c 4 is referred to as a fourth side surface58 c 4, the side surface 58 c 6 is referred to as a sixth side surface58 c 6, and the side surface 58 c 8 is referred to as an eighth sidesurface 58 c 8. The direction in which the third end surface 58 a andthe fourth end surface 58 b face each other is defined as a lengthwisedirection N2 of the wavelength conversion rod 58. An axis passingthrough the center of the third end surface 58 a of the wavelengthconversion rod 58 and the center of the fourth end surface 58 b thereofis defined as an optical axis J1 of the light source apparatus 2.Combined light LW from the light source apparatus 2 exits along theoptical axis J1.

In the present embodiment, the light guiding rod 51 and the wavelengthconversion rod 58 have substantially the same dimensions. A dimension Aof the light guiding rod 51 in the lengthwise direction N1 is greaterthan a dimension B of the light guiding rod 51 in the widthwisedirection thereof (direction perpendicular to lengthwise direction N1).For example, the dimension A is greater than the dimension B by a factorof about a dozen to several dozens. The wavelength conversion rod 58 isconfigured in the same manner as is the light guiding rod 51.

The light guiding rod 51 and the wavelength conversion rod 58 are sodisposed side by side with a gap therebetween that the fifth sidesurface 51 c 5 of the light guiding rod 51 faces the sixth side surface58 c 6 of the wavelength conversion rod 58. In the presentspecification, the description “a light guiding rod and a wavelengthconversion rod are disposed side by side” means that the light guidingrod and the wavelength conversion rod are so disposed that side surfacesthereof face each other.

In the present embodiment, the light guiding rod 51 and the wavelengthconversion rod 58 are so disposed that the two rods are adjacent to eachother and the lengthwise direction N1 of the light guiding rod 51 isparallel to the lengthwise direction N2 of the wavelength conversion rod58. The arrangement described above allows a decrease in the width(dimension in direction perpendicular to optical axis J1) of the lightsource apparatus 2. The lengthwise direction N1 of the light guiding rod51 and the lengthwise direction N2 of the wavelength conversion rod 58are not necessarily parallel to each other and may deviate from theparallel arrangement or incline with each other.

The light source section 62 includes a first light source 62A and asecond light source 62B, as shown in FIG. 3. The first light source 62Ais provided in a position where the first light source 62A faces thelight guiding rod 51 and the wavelength conversion rod 58, as shown inFIG. 2. More specifically, the first light source 62A is provided in aposition where the first light source 62A faces the first side surface51 c 1 of the light guiding rod 51 and the second side surface 58 c 2 ofthe wavelength conversion rod 58. That is, the light source section 62is provided in a position where the light source section 62 faces thelight guiding rod 51 and the wavelength conversion rod 58.

Although not shown, the second light source 62B is also provided in aposition where the second light source 62B faces the light guiding rod51 and the wavelength conversion rod 58, as is the first light source62A. More specifically, the second light source 62B is provided in aposition where the second light source 62B faces the third side surface51 c 3 of the light guiding rod 51 and the fourth side surface 58 c 4 ofthe wavelength conversion rod 58.

The first light source 62A and the second light source 62B have the sameconfiguration and each include a substrate 621 and a plurality of lightemitting diode light sources 622 (LED light sources) mounted on onesurface of the substrate 621 that is the surface facing the lightguiding rod 51 and the wavelength conversion rod 58. In the presentembodiment, the light sources 62A and 62B each include five LED lightsources 622, but the number of LED light sources 622 is not limited to aspecific number. The LED light sources 622 each emit first light L1having a first wavelength band. The first wavelength band is, forexample, a blue wavelength band, for example, from. 400 to 480 nm andhas a peak wavelength of, for example, 445 nm. The light sources 62A and62B may each include a light guide plate, a diffuser plate, a lens, andother optical members as well as the substrate 621 and the LED lightsources 622.

The plurality of LED light sources 622 are so provided as to face thefirst side surface 51 c 1 and the third side surface 51 c 3 of the lightguiding rod 51 and the second side surface 58 c 2 and the fourth sidesurface 58 c 4 of the wavelength conversion rod 58. That is, theplurality of LED light sources 622 that form the first light source 62Aare provided in positions where the LED light sources 622 overlap withthe first side surface 51 c 1 of the light guiding rod 51 and the secondside surface 58 c 2 of the wavelength conversion rod 58 when viewedalong a normal to the first side surface 51 c 1 of the light guiding rod51. Similarly, the plurality of LED light sources 622 that form thesecond light source 62B are provided in positions where the LED lightsources 622 overlap with the third side surface 51 c 3 of the lightguiding rod 51 and the fourth side surface 58 c 4 of the wavelengthconversion rod 58 when viewed along a normal to the third side surface51 c 3 of the light guiding rod 51.

In other words, the plurality of LED light sources 622 that form thefirst light source 62A are so provided as to face the first side surface51 c 1 of the light guiding rod 51 and the second side surface 58 c 2 ofthe wavelength conversion rod 58. The plurality of LED light sources 622that form the second light source 62B are so provided as to face thethird side surface 51 c 3 of the light guiding rod 51 and the fourthside surface 58 c 4 of the wavelength conversion rod 58. The pluralityof LED light sources 622 that form the first light source 62A and thesecond light source 62B are arranged along the lengthwise directions N1and N2 of the rods 51 and 58 with a gap between each of the LED lightsources 622 and an adjacent LED light source 622.

A width D of each of the LED light sources 622 (dimension in directionperpendicular to optical axis J1) is smaller than the sum of a width Bof the light guiding rod 51 and a width C of the wavelength conversionrod 58, that is, the distance from the seventh side surface 51 c 7 ofthe light guiding rod 51 to the eighth side surface 58 c 8 of thewavelength conversion rod 58, as shown in FIG. 2. The width D of each ofthe LED light sources 622 may, however, be equal to the sum of the widthB of the light guiding rod 51 and the width C of the wavelengthconversion rod 58 or greater than the sum of the width B of the lightguiding rod 51 and the width C of the wavelength conversion rod 58.

Further, in the present embodiment, in each of the LED light sources622, the area of the region where the LED light source 622 faces thelight guiding rod 51 is substantially equal to the area of the regionwhere the LED light source 622 faces the wavelength conversion rod 58.That is, a center line of each of the LED light sources 622 that is thecenter line perpendicular to the direction of the width D is locatedbetween the light guiding rod 51 and the wavelength conversion rod 58.

Part of the light L1 emitted from each of the LED light sources 622 orpartial light L11 propagates through the interior of the light guidingrod 51, then exits out of the light guiding rod 51, and functions asblue light that forms part of the illumination light, as shown in FIG.4. Another part of the light L1 or other partial light L12 enters thewavelength conversion rod 58 and then functions as excitation light thatexcites a phosphor contained in the wavelength conversion rod 58. In thefollowing description, the partial light L11 is referred to as firstlight L11, and the other partial light L12 is referred to as excitationlight L12. The first light L11 and the excitation light L12 differ fromeach other in that they enter the different rods but are emitted fromeach single LED light source 622 and belong to the same wavelength band.

As described above, the function of the first light L11, which entersthe light guiding rod 51, and the function of the excitation light L12,which enters the wavelength conversion rod 58, differ from each other.The LED light sources 622 therefore need to emit light having awavelength capable of providing the two functions.

The light guiding rod 51 is made of a light transmissive material, forexample, glass. The first light L11 emitted from the light sources 62Aand 62B enters the light guiding rod 51, which causes the first lightL11 to propagate through the interior thereof.

Out of the four side surfaces 51 c 1, 51 c 3, 51 c 5, and 51 c 7 of thelight guiding rod 51, the fifth side surface 51 c 5 and the seventh sidesurface 51 c 7, which do not face the light source 62A or 62B, are eachprovided with a mirror 64. Further, the first end surface 51 a of thelight guiding rod 51 is provided with a mirror 64. These mirrors 64 areeach formed, for example, of a dielectric multilayer film or a metalfilm formed on a surface of the light transmissive material of which thelight guiding rod 51 is made. From a viewpoint of suppression of opticalloss, the mirrors 64 are each desirably formed of a dielectricmultilayer film.

The wavelength conversion rod 58 contains a phosphor that emits secondlight L2 when excited with the excitation light L12 emitted from thelight source section 62. In the present embodiment, the phosphor isformed of a ceramic phosphor (polycrystal phosphor). The wavelength bandof the second light L2 is, for example, a yellow wavelength band rangingfrom 490 to 750 nm. That is, the second light L2 is yellow fluorescence.The wavelength conversion rod 58 may be formed of a single-crystalphosphor in place of a polycrystal phosphor. The wavelength conversionrod 58 may instead be made of fluorescent glass. The wavelengthconversion rod 58 may still instead be made of a glass or resin binderin which a large number of phosphor particles are dispersed.

Specifically, the wavelength conversion rod 58 is formed, for example,of an yttrium-aluminum-garnet-based (YAG-based) phosphor. ConsiderYAG:Ce, which contains cerium (Ce) as an activator, by way of example,and the wavelength conversion rod 58 can be made, for example, of amaterial produced by mixing raw material powder containing Y₂O₃, Al₂O₃,CeO₃, and other constituent elements with one another and causing themixture to undergo a solid-phase reaction, Y-Al-O amorphous particlesproduced by using a coprecipitation method, a sol-gel method, or anyother wet method, or YAG particles produced by using a spray-dryingmethod, a flame-based thermal decomposition method, a thermal plasmamethod, or any other gas-phase method.

The wavelength conversion rod 58 includes a mirror 63 provided at thethird end surface 58 a of the wavelength conversion rod 58, as shown inFIG. 2. The mirror 63 is formed, for example, of a dielectric multilayerfilm or a metal film.

The light transmissive member 65 is provided between the light sources62A, 62B and the light guiding rod 51, as shown in FIGS. 3 and 4. Inmore detail, the light transmissive member 65 is so provided between theLED light sources 622 of the first light source 62A and the first sidesurface 51 c 1 of the light guiding rod 51 and between the LED lightsources 622 of the second light source 62B and the third side surface 51c 3 of the light guiding rod 51 as to cover the light exiting surface ofeach of the LED light sources 622. The light transmissive member 65 isin contact with the light source section 62 and the light guiding rod51.

The light transmissive member 65 is made, for example, of transparentresin, such as silicone resin, or glass frit. In the case where thelight transmissive member 65 is made of transparent resin, the lighttransmissive member 65 can be readily manufactured. The lighttransmissive member 65 preferably has optical transparency and heatresistance. The light transmissive member 65 also functions as anadhesive that fixes the light sources 62A and 62B to the light guidingrod 51.

The refractive index of the light transmissive member 65 is desirablyequal to the refractive index of the light guiding rod 51. Theconfiguration described above causes no unnecessary refraction when thefirst light L11 enters the light guiding rod 51 from the lighttransmissive member 65, whereby the first light L11 enters the lightguiding rod 51 at a predetermined angle. The amount of first light L11that exits via the side surfaces of the light guiding rod 51 can thus bereduced, whereby the efficiency at which the first light L11 is used canbe increased. The sentence “a refractive index of the light transmissivemember is equal to a refractive index of the light guide” in theappended claims is a concept including a case where the refractiveindices of the light transmissive member and the light guide differ fromeach other in such away that the resultant refraction of light is smallenough not to affect the performance of the light source apparatus dueto a decrease in the light use efficiency.

The light transmissive member 65 is desirably not provided between thelight sources 62A, 62B and the wavelength conversion rod 58, as shown inFIG. 4. When the excitation light L12 enters the wavelength conversionrod 58, the excitation light L12 only needs to reach the phosphor, andthe refraction that occurs when the excitation light L12 enters thewavelength conversion rod 58 does not greatly matter. The lighttransmissive member 65 may therefore not be provided between the lightsources 62A, 62B and the wavelength conversion rod 58. It is, however,noted that the light transmissive member 65 may be provided between thelight sources 62A, 62B and the wavelength conversion rod 58.

The light combiner 53 is disposed in a position where the light combiner53 faces the second end surface 51 b of the light guiding rod 51 and thefourth end surface 58 b of the wavelength conversion rod 58, as shown inFIG. 2. The light combiner 53 combines the first light L11 having exitedout of the light guiding rod 51 with the second light L2 having exitedout of the wavelength conversion rod 58. The light combiner 53 includesa prism 54, which faces the second end surface 51 b of the light guidingrod 51, and a dichroic prism 55, which faces the fourth end surface 58 bof the wavelength conversion rod 58.

The prism 54 is so provided as to be in contact with the second endsurface 51 b of the light guiding rod 51. The prism 54 is formed of atriangular columnar prism having a right-angled isosceles triangularcross section and has a light incident end surface 54 a, a reflectionsurface 54 c, and a light exiting end surface 54 b. The prism 54 has thefunction of deflecting the optical path of the incident first light L11by 90° and causing the deflected first light L11 to exit. That is, theprism 54 causes the first light L11 having exited via the second endsurface 51 b of the light guiding rod 51 to be reflected off thereflection surface 54 c to deflect the optical path of the first lightL11 and causes the reflected first light L11 to exit via the lightexiting end surface 54 b.

The dichroic prism 55 is so provided as to face the fourth end surface58 b of the wavelength conversion rod 58 and the light exiting endsurface 54 b of the prism 54. The dichroic prism 55 has a configurationin which a dichroic mirror 551 is provided in a main body of the prism.The dichroic prism 55 has a cubic shape and has a light incident endsurface 55 a, a light incident end surface 55 b, and a light exiting endsurface 55 c. The dichroic mirror 551 is characterized in that itreflects light having the blue wavelength band and transmits lighthaving the yellow wavelength band. The first light L11 having exited outof the prism 54 is therefore reflected off the dichroic mirror 551 andtravels toward the light exiting end surface 55 c. On the other hand,the second light L2 having exited via the fourth end surface 58 b of thewavelength conversion rod 58 passes through the dichroic mirror 551 andtravels toward the light exiting end surface 55 c.

The dichroic prism 55 thus combines the blue first light L11 havingexited via the second end surface 51 b of the light guiding rod 51 withthe yellow second light L2 having exited via the fourth end surface 58 bof the wavelength conversion rod 58. White combined light LW formed ofthe blue first light L11 and the yellow second light L2 then exits outof the dichroic prism 55. The first light L11 and the second light L2are thus combined with each other in the light combiner 53 as describedabove, whereby the white combined light LW exits out of the lightcombiner 53.

The angle converter 56 is provided on the light exiting side of thelight exiting end surface 55 c of the dichroic prism 55. The angleconverter 56 is formed of a tapered rod having a light incident endsurface 56 a, on which the combined light LW is incident, and a lightexiting end surface 56 b, via which the combined light LW exits. Theangle converter 56 has a truncated pyramidal shape, with thecross-sectional area thereof perpendicular to the optical axis J1increasing with distance along the traveling direction of the combinedlight LW, and the area of the light exiting end surface 56 b istherefore greater than the area of the light incident end surface 56 a.The thus shaped angle converter 56 angularly changes the travelingdirection of the combined light LW, while the combined light LW travelsthrough the interior of the angle converter 56, to the directionparallel to the optical axis J1 whenever the combined light LW istotally reflected off a side surface 56 c of the angle converter 56. Theangle converter 56 thus causes the diffusion angle of the combined lightLW at the light exiting end surface 56 b to be smaller than thediffusion angle of the combined light LW at the light incident endsurface 56 a.

The angle converter 56 is so fixed to the dichroic prism 55 that thelight incident end surface 56 a faces the light exiting end surface 55 cof the dichroic prism 55. That is, the angle converter 56 and thedichroic prism 55 are in contact with each other via an optical adhesive(not shown), and no air gap (air layer) is provided between the angleconverter 56 and the dichroic prism 55. It is noted that the angleconverter 56 may instead be so fixed to the dichroic prism 55 as to bein direct contact therewith, for example, with the aid of an arbitrarysupport member. In either case, it is desirable that no air gap isprovided between the angle converter 56 and the dichroic prism 55. It isfurther desirable that the refractive index of the angle converter 56 isas close as possible to the refractive index of the dichroic prism 55.

The angle converter 56 may be a compound parabolic concentrator (CPC) inplace of the tapered rod. In the case where the angle converter 56 isformed of a CPC, the same effect as that provided when the angleconverter 56 is formed of the tapered rod is provided.

The collimator lens 57 is provided on the light exiting side of thelight exiting end surface 56 b of the angle converter 56. The collimatorlens 57 parallelizes the combined light LW having exited out of theangle converter 56. That is, the collimator lens 57 further increasesthe parallelism of the combined light LW having an angle distributionconverted by the angle converter 56. The collimator lens 57 is formed ofa convex lens. In a case where only the angle converter 56 providessufficient parallelism of the combined light LW, the collimator lens 57may not necessarily be provided.

An effect of the light source apparatus 2 having the configurationdescribed above will be described below.

The first light L11, which is emitted from the LED light sources 622,passes through the light transmissive member 65 and enters the lightguiding rod 51 via the first side surface 51 c 1, as shown in FIG. 4.The first light L11 having entered the light guiding rod 51 reaches anyof the side surfaces 51 c 1, 51 c 3, 51 c 5, and 51 c 7 at an angle ofincidence greater than or equal to the critical angle associated withthe side surface. The first light L11 is reflected off the side surface,and the reflected first light L11 propagates through the interior of thelight guiding rod 51 while repeatedly reflected off the side surfacesand travels toward the first end surface 51 a or the second end surface51 b, as shown in FIG. 3. The first light L11 having traveled toward thesecond end surface 51 b exits via the second end surface 51 b and entersthe prism 54. On the other hand, the first light L11 having traveledtoward the first end surface 51 a is reflected off the mirror 64provided at the first end surface 51 a and travels toward the second endsurface 51 b.

The first light L11 having exited via the second end surface 51 b of thelight guiding rod 51 is then reflected off the reflection surface 54 cof the prism 54, so that the traveling direction of the first light L11is changed, and the reflected first light L11 enters the dichroic prism55, as shown in FIG. 2. A gap (air layer) is desirably provided betweenthe prism 54 and the dichroic prism 55 so that the prism 54 and thedichroic prism 55 are not in direct contact with each other. Providing agap between the prism 54 and the dichroic prism 55 prevents the firstlight L11 incident on the interface between the prism 54 and thedichroic prism 55 at angles of incidence smaller than the critical angleassociated with the interface out of the first light L11 having traveledto the interface and the vicinity thereof from leaking out of the prism54 or the dichroic prism 55, whereby the light use efficiency can beincreased.

On the other hand, the excitation light L12 enters the wavelengthconversion rod 58, as shown in FIG. 4. At this point, the excitationlight L12 excites the phosphor contained in the wavelength conversionrod 58, and the second light L2 is emitted from an arbitrary lightemission point P1. The second light L2 travels omnidirectionally fromthe arbitrary light emission point P1, and the second light L2 travelingtoward the side surfaces 58 c 2, 58 c 4, 58 c 6, and 58 c 8 travelstoward the third end surface 58 a or the fourth end surface 58 b whilebeing repeatedly totally reflected off the side surfaces 58 c 2, 58 c 4,58 c 6, and 58 c 8, as shown in FIG. 2. The second light L2 travelingtoward the fourth end surface 58 b exits via the fourth end surface 58 band then enters the dichroic prism 55. On the other hand, the secondlight L2 traveling toward the third end surface 58 a is reflected offthe mirror 63 provided at the third end surface 58 a and then travelstoward the fourth end surface 58 b.

The first light L11 having entered the dichroic prism 55 is reflectedoff the dichroic mirror 551. On the other hand, the second light L2having entered the dichroic prism 55 passes through the dichroic mirror551. As a result, the blue first light L11 and the yellow second lightL2 are combined with each other, and the white combined light LW exitsvia the light exiting end surface 55 c of the dichroic prism 55. Thecombined light LW having exited out of the dichroic prism 55 isparallelized by the angle converter 56 and the collimator lens 57 andthen emitted from the light source apparatus 2. The combined light LW(illumination light WL) emitted from the light source apparatus 2travels toward the optical integration system 31, as shown in FIG. 1.

The light source apparatus 2 according to the present embodiment isconfigured as follows: The light guiding rod 51, out of which the bluefirst light L11 exits, and the wavelength conversion rod 58, out ofwhich the yellow second light L2 exits, are disposed side by side; thelight combiner 53 is disposed at the second end surface 51 b of thelight guiding rod 51 and the fourth end surface 58 b of the wavelengthconversion rod 58; the light source section 62 is so provided as to facethe first side surface 51 c 1 of the light guiding rod 51 and the sidesurface 58 c 2 of the wavelength conversion rod 58. A compact lightsource apparatus 2 capable of emitting white light can thus be achieved.

The light source apparatus 2 according to the present embodiment has theconfiguration in which the blue light L11 emitted from the light sourcesection 62 is guided by the light guiding rod 51 to the light combiner53. The light source apparatus 2 can efficiently produce blue light inthe simple configuration without a separately prepared phosphor lightsource capable of emitting the blue light, for example, the combinationof an ultraviolet LED and a blue phosphor.

The LED light sources 622 each emit light having the Lambertian lightorientation form. It is therefore difficult in some cases to cause thefirst light L11 emitted from each of the LED light sources 622 to beefficiently incident on an end surface of the light guiding rod 51particularly in a case where the width of the light guiding rod 51(dimension B in FIG. 2) is smaller than the width of each of the LEDlight sources 622 (dimension D in FIG. 2). Therefore, when the LED lightsources 622 are used, it is reasonable to employ the configuration inwhich the LED light sources 622 are so disposed as to face a sidesurface of the light guiding rod 51 and the first light L11 is caused toenter the light guiding rod 51 via the side surface thereof, as in thepresent embodiment.

However, even in the configuration in which the LED light sources 622face a side surface of the light guiding rod 51, the light exitingsurface of each of the LED light sources 622 extends off the sidesurface of the light guiding rod 51 in some cases when the width of eachof the LED light sources 622 is greater than the width of the lightguiding rod 51. In this case, part of the first light L11 emitted fromeach of the LED light sources 622 does not enter the light guiding rod51, resulting in a problem of a decrease in the efficiency at which thefirst light L11 is used. In general, an LED light source having highlight emission efficiency has a large size, and there is therefore ademand for use of a large LED light source.

To solve the problem described above, in the light source apparatus 2according to the present embodiment, since the width of each of the LEDlight sources 622 (dimension D in FIG. 2) is smaller than the sum of thewidth of the light guiding rod 51 (dimension B in FIG. 2) and the widthof the wavelength conversion rod 58 (dimension C in FIG. 2), the lightexiting surface of each of the LED light sources 622 does not extend offthe side surfaces of the light guiding rod 51 or the wavelengthconversion rod 58. A sufficient amount of the first light L11 emittedfrom each of the LED light sources 622 can therefore be caused to enterthe light guiding rod 51 and the wavelength conversion rod 58, wherebythe efficiency at which the first light L11 is used can be increased.Further, since the LED light sources 622 are each shared by the lightguiding rod 51 and the wavelength conversion rod 58, reduction in size,cost, and etendue of the light source apparatus 2 can be achievedwithout an excessive increase in the number of LED light sources 622.

In the light source apparatus 2 according to the present embodiment, inwhich the light transmissive member 65 is interposed between the LEDlight sources 622 and the light guiding rod 51, the first light L11emitted from each of the LED light sources 622 propagates the interiorof the light transmissive member 65 and enters the light guiding rod 51.The configuration described above can suppress unnecessary refraction orreflection as compared with a case where the LED light sources 622 areso disposed as to be separate from the light guiding rod 51 and air isinterposed therebetween, whereby the amount of first light L11 thatenters light guiding rod 51 can be increased. In the present embodiment,in particular, in which the refractive index of the light transmissivemember 65 is equal to the refractive index of the light guiding rod 51,the amount of first light L11 that enters the light guiding rod 51 canbe maximized. The efficiency at which the first light L11 is used cantherefore be increased. In the present embodiment, in particular, inwhich the light transmissive member 65 is in contact with the lightsource section 62 and the light guiding rod 51, loss of the first lightL11 is suppressed, whereby the efficiency at which the first light L11is used can be further increased.

In the light source apparatus 2 according to the present embodiment, theangle converter 56 is provided on the light exiting side of the dichroicprism 55 and can therefore parallelize the combined light LW havingexited out of the dichroic prism 55. Further, the collimator lens 57 isprovided on the light exiting side of the angle converter 56 and cantherefore further increase the parallelism of the combined light LW. Thelight use efficiency in an optical system on the downstream of the lightsource apparatus 2 can thus be increased.

The projector 1 according to the present embodiment, which includes thelight source apparatus 2 described above, allows size reduction andexcels in the light use efficiency.

Second Embodiment

A second embodiment of the present disclosure will be described belowwith reference to FIG. 5.

A light source apparatus according to the second embodiment has the samebasic configuration as that in the first embodiment, but theconfiguration of the light source section differs from that in the firstembodiment. The entire configuration of the light source apparatus willtherefore not be described.

FIG. 5 is a side view showing a schematic configuration of the lightsource apparatus according to the second embodiment.

In FIG. 5, components common to those in FIG. 2 have the same referencecharacters and will not be described.

A light source apparatus 16 includes the light guiding rod 51 (lightguide), the wavelength conversion rod 58 (wavelength converter), thelight source section 62, the light transmissive member 65, the lightcombiner 53, the angle converter 56, and the collimator lens 57, asshown in FIG. 5.

The light source section 62 includes the first light source 62A. Thefirst light source 62A is provided in a position where the first lightsource 62A faces the first side surface 51 c 1 of the light guiding rod51 and the second side surface 58 c 2 of the wavelength conversion rod58. The light source section 62 includes no second light source 62B,unlike in the first embodiment, in which the second light source 62B isprovided in a position where the second light source 62B faces the thirdside surface 51 c 3 of the light guiding rod 51 and the fourth sidesurface 58 c 4 of the wavelength conversion rod 58.

The third side surface 51 c 3 of the light guiding rod 51 is providedwith the mirror 64. The mirror 64 is formed, for example, of adielectric multilayer film or a metal film formed on a surface of thelight transmissive material of which the light guiding rod 51 is made.From the viewpoint of suppression of optical loss, the mirror 64 isdesirably formed of a dielectric multilayer film.

The other configuration of the light source apparatus 16 is the same asthe configuration of the light source apparatus in the first embodiment.

The present embodiment also provides the same effect as that provided bythe first embodiment, that is, a compact, low-etendue light sourceapparatus 16 can be achieved.

The light source apparatus 62 according to the present embodimentincludes only the first light source 62A, which faces the first sidesurface 51 c 1 of the light guiding rod 51, but includes the mirror 64provided on the third side surface 51 c facing away from the first sidesurface 51 c 1 and therefore prevents the first light L11 having enteredthe light guiding rod 51 via the first side surface 51 c 1 from exitingout of the light guiding rod 51 via the third side surface 51 c 3. Theefficiency at which the first light L11 is extracted can therefore beincreased.

Third Embodiment

A third embodiment of the present disclosure will be described belowwith reference to FIG. 6.

A light source apparatus according to the third embodiment has the samebasic configuration as that in the first embodiment, but theconfiguration of the light source section differs from that in the firstembodiment. The entire configuration of the light source apparatus willtherefore not be described.

FIG. 6 is a plan view showing a schematic configuration of a lightsource apparatus 18 according to the third embodiment.

In FIG. 6, components common to those in FIG. 2 have the same referencecharacters and will not be described.

The light source apparatus 18 includes the light guiding rod 51 (lightguide), the wavelength conversion rod 58 (wavelength converter), a lightsource section 72, the light transmissive member 65, the light combiner53, the angle converter 56, and the collimator lens 57, as shown in FIG.6.

The light source section 72 includes a light source for a light guidingrod 73 and a light source for a wavelength conversion rod 74. The lightsource for a light guiding rod 73 and the light source for a wavelengthconversion rod 74 have the same configuration and each includes thesubstrate 621 and a plurality of LED light sources 732 and 742 mountedon one surface of the substrate 621. Specifically, the light source fora light guiding rod 73 includes a plurality of first LED light sources732 arranged along the lengthwise direction N1 of the light guiding rod51 with a gap between each of the first LED light sources 732 and anadjacent first LED light source 732. The plurality of first LED lightsources 732 each emit the first light L11 toward the light guiding rod51. The light source for a wavelength conversion rod 74 includes aplurality of second LED light sources 742 arranged along the lengthwisedirection N2 of the wavelength conversion rod 58 with a gap between eachof the second LED light sources 742 and an adjacent second LED lightsource 742. The plurality of second LED light sources 742 each emit theexcitation light L12 toward the wavelength conversion rod 58.

The first light L1 emitted from each of the first LED light sources 732propagates through the interior of the light guiding rod 51, then exitsout of the light guiding rod 51, and functions as blue light that formspart of the illumination light. On the other hand, the excitation lightL12 emitted from each of the second LED light sources 742 enters thewavelength conversion rod 58 and then excites the phosphor contained inthe wavelength conversion rod 58. As described above, the function ofthe first light L11 emitted from each of the first LED light sources 732and the function of the excitation light L12 emitted from each of thesecond LED light sources 742 differ from each other. Therefore, thefirst LED light sources 732 and the second LED light sources 742 mayeach emit light having an optimized wavelength as the blue light orexcitation light and different from the wavelength of the light emittedfrom the first LED light sources 732 or the second LED light sources 742or may emit light having a wavelength used commonly to the twofunctions.

The other configuration of the light source apparatus 18 is the same asthe configuration of the light source apparatus in the first embodiment.

The present embodiment also provides the same effect as that provided bythe first embodiment, that is, a compact, low-etendue light sourceapparatus 18 can be achieved.

Further, since the blue first light L11 having exited out of the lightguiding rod 51 and the yellow second light L2 having exited out of thewavelength conversion rod 58 are combined with each other into whitecombined light LW, adjusting the balance between the amount of firstlight L11 and the amount of second light L12 can adjust the whitebalance of the white light. As a specific method for adjusting the whitebalance, for example, the light source apparatus 18 may include sensorsthat detect the amounts of first light L11 and second light L2, and theelectric power supplied to the first LED light sources 732 and thesecond LED light sources 742 may be adjusted as appropriate inaccordance with the amount of deviation of each of the amounts of lightdetected with the sensors from a standard value. Further, as a methodfor adjusting the white balance in the design stage, the numbers offirst LED light sources 732 and second LED light sources 742 may beadjusted, or the lengths and thicknesses of the light guiding rod 51 andthe wavelength conversion rod 58 may be adjusted.

Fourth Embodiment

A fourth embodiment of the present disclosure will be described belowwith reference to FIG. 7.

The first embodiment has been described with reference to a liquidcrystal projector, and the fourth embodiment will be described withreference to a projector including a micromirror-type light modulator.

A projector 10 according to the fourth embodiment includes anilluminator 11, a light guide system 12, a micromirror-type lightmodulator 13, and a projection optical apparatus 14, as shown in FIG. 7.The illuminator 11 includes the light source apparatus 2, a color wheel23, and a pickup system 21.

In the fourth embodiment, the light source apparatus 2 according to thefirst embodiment is used as the light source apparatus 2 of theprojector 10. It is, however, noted that the light source apparatus 16according to the second embodiment or the light source apparatus 18according to the third embodiment may be used as the light sourceapparatus 2 of the projector 10. In the fourth embodiment, the lightsource apparatus 2 will not therefore be described.

The color wheel 23 has a configuration in which three color filters,red, green, and blue color filters, are provided on a rotatablesubstrate along the circumferential direction around the axis ofrotation. When the white combined light LW emitted from the light sourceapparatus 2 passes through the color wheel 23 rotating at high speed,the red light LR, the green light LG, and the blue light LB exit out ofthe color wheel 23 in a time division manner.

The pickup system 21 is formed of a first lens 211 and a second lens212. The first lens 211 and the second lens 212 are each formed of aconvex lens. The red light LR, the green light LG, and the blue light LBhaving exited out of the color wheel 23 are transmitted to the lightguide system 12 via the pickup system 21.

The light guide system 12 is formed of a reflection mirror. The lightguide system 12 reflects the red light LR, the green light LG, and theblue light LB emitted from the light source apparatus 2 and causes thereflected color light to be incident on the light modulator 13 in a timedivision manner.

The micromirror-type light modulator 13 is, for example, a digitalmicromirror device (DMD). A DMD has a configuration in which a pluralityof micromirrors are arranged in a matrix. The DMD switches at high speedthe direction in which the light incident thereon is reflected betweenthe direction in which the reflected light enters the projection opticalapparatus 14 and the direction in which the reflected light does notenter the projection optical apparatus 14 by switching the direction inwhich the plurality of micromirrors incline from one to another. Thelight modulator 13 thus sequentially modulates the red light LR, thegreen light LG, and the blue light LB emitted from the light sourceapparatus 2 to produce a green image, a red image, and a blue image.

The projection optical apparatus 14 projects the green image, the redimage, and the blue image on a screen. The projection optical apparatus14 is formed, for example, of a plurality of projection lenses.

The projector 10 according to the present embodiment, which includes thelight source apparatus 2 according to the first embodiment, allows sizereduction and excels in the light use efficiency.

The technical range of the present disclosure is not limited to theembodiments described above, and a variety of changes can be madethereto to the extent that the changes do not depart from the substanceof the present disclosure.

For example, the light source apparatus according to each of theabove-mentioned embodiments has been described with reference to thecase where the refractive index of the light transmissive member isequal to the refractive index of the light guide, and the refractiveindex of the light transmissive member may instead differ from therefractive index of the light guide.

In a case where air is present between the LED light sources and thelight guiding rod, the first light is refracted when it enters the lightguiding rod, so that the amount of light incident on a side surface ofthe light guiding rod at angles of incidence smaller than the criticalangle undesirably increases. To solve the problem described above, theconfiguration in which the light transmissive member is present betweenthe LED light sources and the light guiding rod causes the angle ofrefraction of the first light to decrease as compared with the casewhere air is present between the LED light sources and the light guidingrod, whereby the amount of light incident on a side surface of the lightguiding rod at angles of incidence greater than the critical angleundesirably increases, and the amount of first light that propagatesthrough the light guiding rod increases accordingly. Therefore, evenwhen the refractive index of the light transmissive member differs fromthe refractive index of the light guide, the efficiency at which thefirst light L11 is used can be advantageously increased as compared witha case where no light transmissive member is provided.

The above-mentioned embodiments have been described with reference tothe case where the LED light sources are so disposed as to face a sidesurface of the light guiding rod and the first light enters the lightguiding rod via the side surface. Instead, the light source apparatusaccording to any of the embodiments of the present disclosure may have aconfiguration in which the LED light sources are so disposed as to facean end surface of the light guiding rod and the first light enters thelight guiding rod through the light transmissive member and via the endsurface.

The above-mentioned embodiments have been described with reference tothe case where the wavelength conversion rod contains a phosphor thatemits yellow fluorescence. The wavelength conversion rod may insteadcontain two types of phosphor formed of a phosphor that emits greenfluorescence and a phosphor that emits red fluorescence. In this case,the two types of phosphor may be uniformly mixed with each other in thewavelength conversion rod or may be individually present in separateregions of the wavelength conversion rod.

The above-mentioned embodiments have been described with reference tothe case where the light source apparatus that emits white light, andthe present disclosure is also applicable to a light source apparatusthat emits color light other than white light. For example, a lightsource apparatus may include, for example, a light guiding rod out ofwhich blue light exits and a wavelength conversion rod out of which redlight exits and may emit magenta light that is the combination of theblue light and the red light. Also in this case, the present disclosureallows a compact, low-etendue light source apparatus that emits magentalight to be achieved. Further, the light source apparatus describedabove and the light source apparatus that emits green light may be usedto form a light source apparatus that emits white light.

In the embodiments described above, the configuration example in which aprism and a dichroic prism are used as the light combiner has beenpresented, and another optical member capable of the light combinationmay also be used. For example, a reflection mirror may be used in placeof the prism. Further, a scatterer having a light scattering structureprovided therein may be used in place of the dichroic prism. Examples ofthe scatterer may include glass containing scattering particles and anoptical member containing an anisotropic scattering layer. In the casewhere a scatterer is used, part of the blue light and part of the yellowlight can be scattered in the same direction for the light combinationalthough the light use efficiency decreases to some extent.

The shape, the number, the arrangement, the material, and other specificconfigurations of the components that form the light source apparatusesare not limited to those in the embodiments described above and can bechanged as appropriate.

The above-mentioned first embodiment has been described with referenceto the case where the present disclosure is applied to a transmissiveliquid crystal projector, and the present disclosure is also applicableto a reflective liquid crystal projector. The term “transmissive” usedherein means that a liquid crystal light valve including a liquidcrystal panel or any other component transmits light. The term“reflective” means that the liquid crystal light valve reflects light.

The above-mentioned first embodiment has been described with referenceto a projector including three liquid crystal panels. The presentdisclosure is also applicable to a projector using only one liquidcrystal light valve and a projector using four or more liquid crystallight valves.

The above-mentioned embodiments have been described with reference tothe case where the light source apparatus according to any of theembodiments of the present disclosure is incorporated in a projector,but not necessarily. The light source apparatus according to any of theembodiments of the present disclosure may also be used as a lightingapparatus, a headlight of an automobile, and other components.

What is claimed is:
 1. A light source apparatus comprising: a lightsource section that emits first light and excitation light having afirst wavelength band; a light guide that causes the first light emittedfrom the light source section to propagate; a wavelength converterincluding a phosphor that emits second light having a wavelength banddifferent from the wavelength band of the excitation light when thephosphor is excited with the excitation light emitted from the lightsource section; and a light combiner that combines the first lighthaving exited out of the light guide with the second light having exitedout of the wavelength converter, wherein the light guide and thewavelength converter are disposed side by side, and a light transmissivemember that transmits the first light is provided between the lightsource section and the light guide.
 2. The light source apparatusaccording to claim 1, wherein the light guide has a first end surfaceand a second end surface that face each other and a first side surfacethat intersects the first end surface and the second end surface, thewavelength converter has a third end surface and a fourth end surfacethat face each other and a second side surface that intersects the thirdend surface and the fourth end surface, the light source section isprovided in a position where the light source section faces the firstside surface and the second side surface, and the light transmissivemember is provided between the light source section and the first sidesurface.
 3. The light source apparatus according to claim 2, wherein thelight combiner is disposed in a position where the light combiner facesthe second end surface and the fourth end surface.
 4. The light sourceapparatus according to claim 3, wherein the light combiner includes aprism that faces the second end surface and a dichroic prism that facesthe fourth end surface.
 5. The light source apparatus according to claim1, wherein the light transmissive member is made of transparent resin.6. The light source apparatus according to claim 1, wherein a refractiveindex of the light transmissive member is equal to a refractive index ofthe light guide.
 7. The light source apparatus according to claim 1,wherein the light transmissive member is in contact with the lightsource section and the light guide.
 8. The light source apparatusaccording to claim 1, wherein the light guide and the wavelengthconverter are so disposed that the light guide and the wavelengthconverter are adjacent to each other and a lengthwise direction of thelight guide is parallel to a lengthwise direction of the wavelengthconverter.
 9. The light source apparatus according to claim 1, whereinthe light source section includes a light emitting diode light source.10. The light source apparatus according to claim 1, wherein the firstlight is blue light and the second light is yellow fluorescence, and thelight combiner combines the first light and the second light with eachother into white combined light, and the white combined light exits outof the light combiner.
 11. A projector comprising: the light sourceapparatus according to claim 1; a light modulator that modulates lightfrom the light source apparatus in accordance with image information;and a projection optical apparatus that projects the light modulated bythe light modulator.